Microbial inoculant and garbage enzyme reduced cadmium (Cd) uptake in Salvia miltiorrhiza (Bge.) under Cd stress

• Published in: Ecotoxicology and environmental safety Vol. 192; p. 110311
• Main Authors: Wei, Xuemin, Cao, Pei, Wang, Gang, Han, Jianping
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.04.2020
• Subjects: Abietanes - metabolism; Alkenes - analysis; Bioactive compounds; Biodegradation, Environmental; Biomass; Cadmium - pharmacokinetics; Cadmium - toxicity; Heavy metal; Herbal quality; Microbial remediation; Plant Roots - drug effects; Polyphenols - analysis; Rhizosphere; Rhizospheric microorganisms; Salvia miltiorrhiza - chemistry; Salvia miltiorrhiza - drug effects; Salvia miltiorrhiza - metabolism; Soil Microbiology; Soil Pollutants - toxicity; Microbial remediation; LDA; SA; Heavy metal; PCA; LEfSe; TTs; Herbal quality; Rhizospheric microorganisms; Bioactive compounds; ICP-MS; MI; PGPR; TEM; GE; MIGE
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2020.110311

The uptake and accumulation of cadmium (Cd) in Salvia miltiorrhiza (Bge.) negatively affects the quality of its harvested roots, and seriously threatens human health. This study investigates the effect of a microbial inoculant (MI) and garbage enzyme (GE) on Cd uptake, the accumulation of bioactive compounds, and the community composition of microbes in the rhizosphere soil of S. miltiorrhiza under Cd stress. S. miltiorrhiza seedlings were transplanted to Cd-contaminated pots and irrigated with an MI, GE, a combination of an MI and GE (MIGE) or water (control). The results indicated that treatments with an MI, GE or MIGE can reduce Cd uptake in S. miltiorrhiza. The MIGE treatment had greater efficiency in reducing Cd uptake than the control (reduction by 37.90%), followed by the GE (25.31%) and MI (5.84%) treatments. Treatments with an MI, GE and MIGE had no significant impact on fresh and dry root biomass. Relative to the control, the MI treatment had the highest efficiency in increasing the accumulation of total tanshinones (an increase of 40.45%), followed by the GE treatment (40.08%), with the MIGE treatment (9.90%) treatment not having a more favorable effect than the separate application of an MI or GE. The salvianolic acid content for all groups was higher than the standard prescribed by Chinese pharmacopoeia, notwithstanding a slightly lower level in the treated groups relative to the control. In addition, metagenomic analysis indicated changes in the relative abundance of soil microbes associated with the bioremediation of heavy metals. The relative abundances of Brevundimonas, Microbacterium, Cupriavidus and Aspergillus were significantly greater in the treated groups than in the Control. These results suggest that using MI and GE, either separately or together, may not only improve the quality of S. miltiorrhiza but may also facilitate the microbial remediation of soil contaminated with Cd. [Display omitted] •The effects of an MI and GE on Cd uptake in Saliva miltiorrhiza were investigated.•The MI, GE, and MIGE treatments decreased Cd uptake by 5.84–37.90%.•The GE and MI increased the accumulation of tanshinones by 40.08% and 40.45%.•MI and GE exhibited potential for microbial remediation of Cd-contaminated soil.•This is the first report on the effects of GE on reducing Cd uptake in herbs.